With advancement of the society and the promotion of life quality, variable designs occur to strollers and children toys. Traditional inflatable tires have an outer tire layer made of rubber and a hollow inner tire layer. These traditional inflatable tires must be filled with air into inner tire layer when used, which makes the inflatable tires have the risk of implosion or become an annoyance due to having to inflate the tires from time to time.
In view of the above deficiencies of inflatable tires, a non-inflatable tire is developed. However, the entire traditional non-inflatable tire itself is constructed by foamed material such as EVA with foaming agent. Because the traditional non-inflatable tire is thoroughly manufactured by foam molding, the tread patterns formed on the tire fail to be of a taper near vertical angle corresponding to the die relief. Moreover, the properties of the EVA itself are different from those of the rubber, so that the characteristics of the traditional non-inflatable tire, such as wear resistance and resiliency, are worse.
An improved tire for the above non-inflatable tire is disclosed in U.S. Pat. No. 2002/0036040A1 where the tire has an outer tire layer 10, an inner tire layer 20, and a rim 30 as the exploded perspective view shown in FIG. 1. The inner tire layer 20 is made of foamed material and the outer tire layer 10 is made of rubber to form an annular hollow interior. The manufacture processes include first, respectively producing the outer tire layer 10, inner tire layer 20, and rim 30, next, mounting the inner tire layer 20 around the rim 30, and finally, assembling the outer tire layer 10 around the outer periphery of the inner tire layer 20. It is the advantage of this type of traditional non-inflatable tire that the tire is more resilient due to the inner tire layer being made of foamed material and the special tread patterns are easily formed on the outer tire layer to upgrade wear resistance of the tire due to the outer tire layer being made of rubber. However, because this kind of non-inflatable tire must be mechanically assembled through two steps, the reliability of connection among the outer tire layer 10, inner tire layer 20, and rim 30 is low, which results in the outer tire layer 10 or inner tire layer 20 having tendency of being escaped from the rim 30 and causes safety concerns when the tire is used in addition to shorter lifespan.